Pull-out and pull-over failure probability of residential house roods due to extreme wind speeds: A case study in Malate, Metro Manila (2013)
ALVAREZ, Isiah Paul
COLOBONG, John Anthony
TAN, Adam Benedict
– About fifteen to twenty typhoons enter the Philippine Area of responsibility every year, causing devastating effects to residential structures in many parts of the country. Failures of roofs usually occur because of the strong uplift against the typhoon. In this regard, we have investigated the probability of pullout and pullover failures of roof panels of low-rise residential structures when subjected to extreme wind speeds (such as typhoon). The area considered in this study is a part of Malate Manila, Philippines more specifically the vicinity which consists of Barangays # 707-721, where not designed based on standards of specifications specified by the appropriate codes. The analysis of the roof panels are based on the wind load provisions on pullout as well as pullover failure in the National Structural Code of the Philippines (NSCP-2010). The study uses stochastic analysis in determining the probability of failure is established through the comparison of the capacity or resistance of a given roof and the wind load which serves as the uplift force. These are obtained by data gathering which includes primarily the roofing details of residential structures obtained through site surveying; on the other hand, annual maximum wind data were gathered from the Philippine Atmospheric Geophysical and Astronomical services administration (PAGASA). These data were used in generating 50-year typhoon return periods for wind uplift pressures using the Generalized Extreme Value (GEV) Distribution. With the aid of Geographic Information System database, the analyzed fata for the residential structures was stored and made into a hazard map which may serve as a reference in determining the impending state of non-engineered residential houses whenever typhoons would strike. For the purpose of preparing for possible impeding disasters brought about by typhoons, the reference map would be of help to the residents in the concerned area of Malate, Manila predicting the vulnerability of their roofs.
Dr. Lessandro Estelito O. Garciano